{*****************************************}

{                                         }

{             FastReport v2.3             }

{            Report DB dataset            }

{                                         }

{  Copyright (c) 1998-99 by Tzyganenko A. }

{                                         }

{*****************************************}



unit FR_DBSet;



interface



{$I FR.inc}



uses

  SysUtils, Windows, Messages, Classes, FR_DBRel, FR_DSet

{$IFDEF IBO}

 , IB_Components

{$ELSE}

 , DB

{$ENDIF};



type

  TfrDBDataSet = class(TfrDataset)

  private

{$IFDEF IBO}

    FDataSet: TIB_DataSet;

    FDataSource: TIB_DataSource;

{$ELSE}

    FDataSet: TDataSet;

    FDataSource: TDataSource;

{$ENDIF}

    FOpenDataSource, FCloseDataSource: Boolean;

    FOnOpen, FOnClose: TNotifyEvent;

    FBookmark: TfrBookmark;

    FEof: Boolean;

{$IFDEF IBO}

    procedure SetDataSet(Value: TIB_DataSet);

    procedure SetDataSource(Value: TIB_DataSource);

{$ELSE}

    procedure SetDataSet(Value: TDataSet);

    procedure SetDataSource(Value: TDataSource);

{$ENDIF}

  protected

    procedure Notification(AComponent: TComponent;

                           Operation: TOperation); override;

  public

    constructor Create(AOwner: TComponent); override;

    procedure Init; override;

    procedure Exit; override;

    procedure First; override;

    procedure Next; override;

    procedure Open;

    procedure Close;

    function Eof: Boolean; override;

    function GetDataSet: TfrTDataSet;

  published

    property CloseDataSource: Boolean read FCloseDataSource write FCloseDataSource default False;

{$IFDEF IBO}

    property DataSet: TIB_DataSet read FDataSet write SetDataSet;

    property DataSource: TIB_DataSource read FDataSource write SetDataSource;

{$ELSE}

    property DataSet: TDataSet read FDataSet write SetDataSet;

    property DataSource: TDataSource read FDataSource write SetDataSource;

{$ENDIF}

    property OpenDataSource: Boolean read FOpenDataSource write FOpenDataSource default True;

    property RangeBegin;

    property RangeEnd;

    property RangeEndCount;

    property OnCheckEOF;

    property OnClose: TNotifyEvent read FOnClose write FOnClose;

    property OnFirst;

    property OnNext;

    property OnOpen: TNotifyEvent read FOnOpen write FOnOpen;

  end;





implementation



uses FR_Class;



type

  EDSError = class(Exception);



constructor TfrDBDataSet.Create(AOwner: TComponent);

begin

  inherited Create(AOwner);

  FOpenDataSource := True;

end;



procedure TfrDBDataSet.Notification(AComponent: TComponent; Operation: TOperation);

begin

  inherited Notification(AComponent, Operation);

  if Operation = opRemove then

    if AComponent = FDataSource then

      FDataSource := nil

    else if AComponent = FDataSet then

      FDataSet := nil

end;



{$IFDEF IBO}

procedure TfrDBDataSet.SetDataSet(Value: TIB_DataSet);

{$ELSE}

procedure TfrDBDataSet.SetDataSet(Value: TDataSet);

{$ENDIF}

begin

  FDataSet := Value;

  FDataSource := nil;

end;



{$IFDEF IBO}

procedure TfrDBDataSet.SetDataSource(Value: TIB_DataSource);

{$ELSE}

procedure TfrDBDataSet.SetDataSource(Value: TDataSource);

{$ENDIF}

begin

  FDataSource := Value;

  if Value <> nil then

    FDataSet := nil;

end;



function TfrDBDataSet.GetDataSet: TfrTDataSet;

begin

  if (FDataSource <> nil) and (FDataSource.DataSet <> nil) then

    Result := TfrTDataSet(FDataSource.DataSet)

  else if FDataSet <> nil then

    Result := TfrTDataSet(FDataSet)

  else

  begin

    raise EDSError.Create('Unable to open dataset ' + Name);

    Result := nil;

  end;

end;



procedure TfrDBDataSet.Init;

begin

  Open;

  FBookmark := frGetBookmark(TfrTDataSet(GetDataSet));

  FEof := False;

end;



procedure TfrDBDataSet.Exit;

begin

  if FBookMark <> frEmptyBookmark then

  begin

    if (FRangeBegin = rbCurrent) or (FRangeEnd = reCurrent) then

      frGotoBookmark(TfrTDataSet(GetDataSet), FBookmark);

    frFreeBookmark(TfrTDataSet(GetDataSet), FBookmark);

  end;

  FBookMark := frEmptyBookmark;

  Close;

end;



procedure TfrDBDataSet.First;

begin

  if FRangeBegin = rbFirst then

    GetDataSet.First

  else if FRangeBegin = rbCurrent then

    frGotoBookmark(GetDataSet, FBookmark);

  FEof := False;

  inherited First;

end;



procedure TfrDBDataSet.Next;

var

  b: TfrBookmark;

begin

  FEof := False;

  if FRangeEnd = reCurrent then

  begin

    b := frGetBookmark(GetDataSet);

    if frIsBookmarksEqual(GetDataSet, b, FBookmark) then

      FEof := True;

    frFreeBookmark(GetDataSet, b);

    System.Exit;

  end;

  GetDataSet.Next;

  inherited Next;

end;



function TfrDBDataSet.Eof: Boolean;

begin

  Result := inherited Eof or GetDataSet.Eof or FEof;

end;



procedure TfrDBDataSet.Open;

begin

  if FOpenDataSource then GetDataSet.Open;

  if Assigned(FOnOpen) then FOnOpen(Self);

end;



procedure TfrDBDataSet.Close;

begin

  if Assigned(FOnClose) then FOnClose(Self);

  if FCloseDataSource then GetDataSet.Close;

end;







end.